72010410 NIP & Digital Fabrication Conference nip digi fabric conf 2169-4451 Society of Imaging Science and Technology 7003 Kilworth Lane, Springfield, VA 22151, USA 10.2352/ISSN.2169-4451.1999.15.1.art00078_2 2169-4451(19990101)1999:2L.679;1- nip_v1999n2/splitsection78.xml /ist/nipdf/1999/00001999/00000002/art00078 Articles Near-IR Absorption in Magnesiumphthalocyanine Complexes Mizuguchi J. Endo A. Matsumoto S. 01 01 1999 1999 2 679 682 1999

Magnesiumphthalocyanine (MgPc) is a blue pigment whose X-phase is known to exhibit an intense near-IR absorption. The near-IR absorption of MgPc has been investigated from the standpoints of exciton coupling effects on the basis of the crystal structure. Two kinds of six-coordinate MgPc complexes were grown from solution and their structures were analyzed: MgPc/(H2O)2·(N-methyl-2-pyrrolidone)2 (crystal 1) and MgPc/(2-methoxyethanol)2 (crystal 2). In both crystals, two oxygen atoms of the solvent molecule are coordinated to the central Mg atom above and below the molecular plane, forming a distorted sp3d2 octahedron. Of these crystals, only crystal 1 exhibits a near-IR absorption whose spectral shape is quite similar to that of the X-phase. In addition, the X-phase is also found to contain two water-molecules in the normal ambient atmosphere. The near-IR absorption in both crystal 1 and the X-phase can reasonably be interpreted as arising from exciton coupling effects based on the molecular arrangement of MgPc/(H2O)2.